Thursday, May 1, 2008

Features of PIC microcontroller

New to PIC ??

Let us see the dynamic features of PIC which has made it a better choice than other microcontrollers

Features of PIC microcontroller

1.code efficiency - The PIC 8 bit microcontroller is based on Harvard architecture, which means there are separate internal buses for memory and data. The throughput rate is therefore increased due to simultaneous access to both data and program memory. It would be easier if you have known about von neumann architecture which has common bus for memory and data. - All the instructions fit into a 12 or 14 bit program memory word. There is no likelihood of software jumping onto the DATA section of a program and trying to execute DATA as instructions.
3.Instruction set - There are 33 instructions you have to learn in order to write software for the 16C5x family. The lesser number of instruction eases our job while writing program in assembly language.
4.Speed - The PIC has an internal divide by 4 connected between the oscillator and the internal clock bus(note : we know their is a divide by 2 in a 8085 microprocessor where we connect a 6Mhz clock inorder to operate the microprocessor at a speed of 3Mhz). The PIC is very fast to work with. The speed of PIC16F877A is 20Mhz but it can even operate at a speed of 30Mhz. some PIC in 18Fx family can be operated at 40Mhz.
5.Static Operation - The PIC is a fully static microcontroller, in other words, if you top the clock, all the register contents are maintained. In practise you would not actually do this, you would place the PIC into a Sleep mode-this stops the lock and sets up various flags within th ePIC to allow you to know what state it was in before the Sleep. In sleep, the PIC takes only its standby current which can be less than 1uA. The need for sleep mode can be easily understood by considering the Fire alarm circuit, since the circuit has to be activated only when their is a fire, the rest of the time the PIC can be made to be in its sleep mode and wake up when their is fire thus saving the power required for the operation of PIC.
6.Drive Capability - The PIC has a high output drive capability and can directly drive LEDs and TRIACs etc. Any I/O pin can sink 25mA or 100mA for the whole device.
7.Options - A range of speed, temperature, package, I/O lines, timer functions, serial communication, A/D and memory sizes is available from the PIC family to suit virtually all your requirements.

PIC microcontroller can be programmed using embedded C. some of the compilers which i have used are mikroC, CCS C compiler and Mplab. It is easier to program in embedded C rather than programming in assembly language. The demo version of these compilers can compile upto 2KB of program memory.

1 comment:

vishal sharma said...

Very nice blog...
Great information provided. We also provide PIC Microcontroller Training in Noida. I appreciate your work.